It was one of the defining television dramas of its time and a career-making role for the then relatively unknown Derek Jacobi. Now he is to reprise his role in I, Claudius for a whole new audience. The series, to be aired by BBC Radio in January, will see him return to the pivotal role in what was widely considered to be one of the greatest pieces of TV drama after a gap of 30 years.

Based on two novels by Robert Graves, the epic tale chronicles the fortunes of Rome's rulers in the first century AD, as seen through the eyes of Claudius - who rose to power at the age of 49 - in the form of a secret autobiography. Claudius, who succeeded the psychotic Caligula, was an unusual choice for emperor because of his physical disabilities. Some scholars now believe he may have had cerebral palsy.

Sir Derek was keen to get involved in the revival and showed no reluctance over returning to the role that won him a best actor Bafta in 1977, according to Frank Stirling, the series' producer. "He found it a very pleasant trip down memory lane," he said. "I wish there were some great story to tell about how I had persuaded him, but he instantly said that he'd be delighted to do it."

The drama has proved an enduring success for the BBC and regularly tops its sales of drama series on DVD. It was also named as one of the top three UK drama series of all time in a poll conducted by the British Film Institute.

The revamped eight-part serialisation has been staged for BBC Radio 2 and will be broadcast from 12 January. Though the 1976 TV version - which also starred Siân Phillips, Brian Blessed and John Hurt - combined Graves's 1934 novel and its sequel, Claudius the God, the radio revival will stick solely to the first book.

Mr Stirling said: "What's interesting is that when you watch the original TV series, he has to age from a teenager right through to old age. Now he is a middle-aged man, and he can just as easily turn his hand to playing a youth. Because of the span of ages, there is really no wrong age to play Claudius."

There is still a great affection for I, Claudius. Dr Who actor David Tennant said that, for him, viewing the whole series on DVD for the first time was the highlight of the past year. "It's a real gem, the best BBC series of the 1970s. There's a clutch of great performances in it. Derek Jacobi in particular is a genius."

Sir Derek said recently: "I think most actors rather enjoy having a role they are identified with. And it's not as if I could get typecast. There are not too many stuttering, limping, twitching emperors around.

Even so, his initial starring role was nearly not to be: "They'd tried everybody for Claudius before they tried me: Charlton Heston, even Ronnie Barker."

Sir Derek, 68, has recently been filming the movie The Riddle, a murder-mystery about the discovery of an unpublished Charles Dickens novel.